Modeling the Magnetocaloric Effect of La_0.8MnO₃ by the Mean-Field Theory

In this research paper, our central focus is upon the investigation of the mean-field approach based on the Bean-Rodbell model applied to the magnetic properties of the compound La_0.8MnO₃. Using the isotherm, we determined the value of the mean-field exchange parameter λ. After using a MATLAB software, the values of J, g, and M₀ were identified and compared with the experimental values. Another MFSS software running with MATLAB program was invested to determine the theoretical variation of magnetization as a function of magnetic field at different temperatures, the variation of magnetic entropy, and the nature of transition compared with the experimental values provided by data and Maxwell relation. A good accordance has been recorded between the experimental and theoretical curves. The values of ∆S_max and RCP which are equal to 3.63 J kg⁻¹ K⁻¹ and 83.38 J kg⁻¹, respectively. They were determined by the Maxwell relation and were compared with those determined by the Bean-Rodbell model which are equal to 4.01 J kg⁻¹ K⁻¹ for ∆S_max and to 97.36 J kg⁻¹ for the RCP at 2 T respectively.